Apparatuses of this kind are already known in the prior art. A first type of apparatus comprises a couple of counter-rotating cylinders whose length is basically equal to the width of the material to be cut.
A blade is fixed longitudinally on one of the cylinders, projecting from it, while a longitudinal groove is provided on the second cylinder, the length of said groove equating the length of the blade. At each complete turn of the cylinders, the blade penetrates in the groove, cutting the material. Fine tuning these kinds of apparatuses is a critical operation, especially as concerns the penetration of the blade in the groove, which depends directly on the rotational velocities of the cylinders being equal.
Besides, their synchronism must be maintained in time, which cannot always be achieved, for instance due to wear phenomena of the movement transmission gears and the supports. The correct calculation of the groove size is a further serious problem which arises in designing these apparatuses, as the cutting blade does not enter and exit from it in a perfectly radial way, but with a movement component having a tangent direction.
The groove width must be just such as to permit this movement and not larger, otherwise the cutting operation would be jeopardized. It should also be stressed that in this first type of known apparatus, all the fine tuning operations bring about a remarkable waste of time.
A second type of known apparatus provides for a transverse guillotine cutting.
This second type of apparatus has basically the same drawbacks as the one of the first type.
Besides, these known apparatuses have a complex and bulky structure which limits or at least complicates their maintenance.